Controlling the flow of a coolant fluid through a cooling system of an internal combustion engine

ABSTRACT

Examples of techniques for controlling the flow of a coolant fluid through a cooling system of an internal combustion engine are disclosed. In one example implementation, a method includes calculating, by a processing device, a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the internal combustion engine. The method further includes converting, by the processing device, the minimum zone flow rate into a desired actuator position for a flow control valve to enable the flow control valve to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system. The method further includes enabling, by the processing device, the flow control valve to change from a current actuator position to the desired actuator position.

INTRODUCTION

The present disclosure relates generally to internal combustion engines and more particularly to controlling the flow of a coolant fluid through a cooling system of an internal combustion engine.

A vehicle, such a car, a truck, a motorcycle, or any other type of automobile may be equipped with an internal combustion engine to provide a source of power for the vehicle. Power from the engine can include mechanical power (to enable the vehicle to move) and electrical power (to enable electronic systems, pumps, etc. within the vehicle to operate). As an internal combustion engine operates, the engine and its associated components generate heat, which can damage the engine and its associated components if left unmanaged.

To reduce heat in the engine, a coolant system circulates a coolant fluid through cooling passages within the engine. The coolant fluid absorbs heat from the engine and is then cooled via a heat exchanger in a radiator when the coolant fluid is pumped out of the engine and into the radiator. Accordingly, the coolant fluid becomes cooler and is then circulated back through the engine to cool the engine and its associated components.

SUMMARY

In one exemplary embodiment, a computer-implemented method for controlling the flow of a coolant fluid through a cooling system of an internal combustion engine includes calculating, by a processing device, a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the internal combustion engine. The method further includes converting, by the processing device, the minimum zone flow rate into a desired actuator position for a flow control valve to enable the flow control valve to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system. The method further includes enabling, by the processing device, the flow control valve to change from a current actuator position to the desired actuator position.

In another exemplary embodiment, a system controlling the flow of a coolant fluid through a cooling system of an internal combustion engine includes a memory including computer readable instructions and a processing device for executing the computer readable instructions for performing a method. In examples, the method includes calculating, by a processing device, a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the internal combustion engine. The method further includes converting, by the processing device, the minimum zone flow rate into a desired actuator position for a flow control valve to enable the flow control valve to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system. The method further includes enabling, by the processing device, the flow control valve to change from a current actuator position to the desired actuator position.

In yet another exemplary embodiment a computer program product for controlling the flow of a coolant fluid through a cooling system of an internal combustion engine includes a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a processing device to cause the processing device to perform a method. In examples, the method includes calculating, by a processing device, a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the internal combustion engine. The method further includes converting, by the processing device, the minimum zone flow rate into a desired actuator position for a flow control valve to enable the flow control valve to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system. The method further includes enabling, by the processing device, the flow control valve to change from a current actuator position to the desired actuator position.

In some embodiments of the present disclosure, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a coolant fluid temperature at an inlet of the zone. In some embodiments of the present disclosure, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a heat flow in the zone. In some embodiments of the present disclosure, the method further includes adjusting the minimum zone flow rate based at least in part on ambient pressure information. In some embodiments of the present disclosure, the method further includes determining that the zone of the cooling system is an engine head zone. In some embodiments of the present disclosure, the method further includes revising the desired actuator position for the flow control valve based at least in part on a radiator flow rate. In some embodiments of the present disclosure, converting the minimum zone flow rate into a desired actuator position is based at least in part on an inverted flow model. In some embodiments of the present disclosure, the desired actuator position is a percentage of opening of the flow control valve.

The above features and advantages, and other features and advantages, of the disclosure are readily apparent from the following detailed description when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, advantages, and details appear, by way of example only, in the following detailed description, the detailed description referring to the drawings in which:

FIG. 1 depicts a vehicle engine including a valve controller for controlling the flow of a coolant fluid through a cooling system of an internal combustion engine, according to embodiments of the present disclosure;

FIG. 2 depicts a flow diagram of a method for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine, according to embodiments of the present disclosure;

FIG. 3A depicts a block diagram of an invertible flow model for determining estimated flow of the flow control valve, according to embodiments of the present disclosure;

FIG. 3B depicts a block diagram of an inverted flow model used to convert a flow request into an actuator position for the flow control valve, according to embodiments of the present disclosure;

FIG. 4 depicts a flow diagram of a method for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine, according to embodiments of the present disclosure; and

FIG. 5 depicts a block diagram of a processing system for implementing the techniques described herein, according to embodiments of the present disclosure.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. As used herein, the term module refers to processing circuitry that may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

The technical solutions described herein provide for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine. In particular, the present techniques regulate coolant fluid flow through zones of the engine to prevent the coolant fluid from boiling within a zone. To accomplish this, a minimum zone flow rate for the coolant fluid for a zone is calculated and converted into a desired actuator position for a flow control valve within the cooling system. The desired actuator position is the position of the flow control valve that provides the minimum zone flow rate of the coolant fluid to the particular zone of the cooling system. The flow control valve then changes actuator position from a current actuator position to a desired actuator position to provide the minimum zone flow rate of the coolant fluid through the zone.

Accordingly, thermal stress on the engine is reduced, preventing possible damage to or failure of the engine and its components. Modern engines have become more efficient and combusting fuel, which causes an increase in the operating temperature of the engine. By controlling the flow of the coolant fluid, it is possible to operate the engine at the highest temperature possible without comprising the hardware integrity of the engine. This increases engine and fuel efficiency while preventing failure of the engine.

FIG. 1 depicts a vehicle engine 100 including a valve controller 102 for controlling the flow of a coolant fluid through a cooling system of an internal combustion engine 100, according to embodiments of the present disclosure. The vehicle engine 100 includes at least a main coolant pump (“pump”) 104, an engine block 110, an engine head 112, other engine components 114 (e.g., a turbocharger, an exhaust gas re-circulator, etc.), a main rotary value 130, an engine oil heater 116, a transmission oil heater 118, a radiator 120, a flow control valve (FCV) 160, and a block rotary valve (BRV) 162. Each of the components (e.g., the engine block 110, the engine head 112, the other components 114, etc.) can be referred to as a “zone” of the vehicle engine 100. For example, the engine block 110 can be referred to as an engine block zone, the engine head 112 can be referred to as an engine head zone, etc.

The main rotary valve 130 includes a first valve (or chamber) 140 having a first inlet 141, a second inlet 142, and an outlet 143. The main rotary valve 130 also includes a second valve (or chamber) 150 having an inlet 151, a first outlet 152, and a second outlet 153. The various components of the vehicle engine 100 are connected and arranged as shown in FIG. 1 according to embodiments of the present disclosure, and the solid lines among the components represent the fluid connections among the components, with arrows representing the flow direction of the fluid.

Coolant fluid is cooled by the radiator 120 and is pumped out of the radiator by the pump 104 back into the engine block 110, the engine head 112, and the other components 114 (collectively, the “inlet” of the engine). Coolant fluid cooled by the radiator 120 can also be pumped directly into the first inlet 141 of the main rotary valve 130. Managing the flow out of the radiator 120 enables mixing cold coolant with hot coolant in order to provide the coolant to the vehicle engine 100 at a desired temperature.

The valve controller 102 controls the flow of coolant fluid through the vehicle engine 100 by opening and closing (wholly or partially) the first valve 140 and the second valve 150. In particular, the valve controller 102 can cause the second valve 150 to direct flow from the engine block 110 and the engine head 112 into the radiator 120 and/or the radiator bypass 122 through the first outlet 152 and the second outlet 153. Similarly, the valve controller 102 can cause the first valve 140 to direct flow from either the first inlet 141 and/or the second inlet 142 into the engine oil heater 116 and the transmission oil heater 118 through the outlet 143.

The first inlet 141 (also referred to as the “cold inlet”) receives cooled coolant fluid via the pump 104 from the radiator 120. The second inlet 142 (also referred to as the “warm inlet”) receives warm coolant fluid (warm relative to the cooled coolant fluid) after it is pumped by the pump 104 through the engine block 112/engine head 112 and the other components 114. The warm coolant fluid is warmed as it passes through the engine block 110, the engine head 112, and/or the other components. Accordingly, depending on the state of the first valve 140, the first valve 140 can provide either cooled coolant fluid or warm coolant fluid to the engine oil heater 116 and the engine transmission oil heater 118.

To reduce an influx of cool coolant fluid in the engine block 110 and the engine head 112, a flow control valve (FCV) 160 can be closed between the engine block 110/engine head 112 and the second valve 150 of the main rotary valve 130. In particular, an inlet of the FCV 160 is in fluid communication (directly and/or indirectly) with an outlet of the engine block 110 and an outlet of the engine head 112, and an outlet of the FCV 160 is in fluid communication with the inlet 151 of the second valve 150 of the main rotary valve 130 and with an inlet of other components 114.

When the FCV 160 is closed, the flow of coolant fluid into the radiator 120 is stopped so the coolant fluid is not cooled by the radiator 120. This prevents cooled coolant fluid from cycling back into the engine block 110/engine head 112. The valve controller 102 controls the FCV 160 to open and close (wholly or partially) the FCV 160 based at least in part on state changes of the main rotary valve 130. According to some embodiments, the FCV 160 is partially closed (e.g., closed 25%, closed 50%, closed 80%, etc.) to achieve a desired flow (e.g., to maintain a consistent temperature through the vehicle engine 100 or within a particular zone of the vehicle engine 100).

In some situations, the engine block 110 and the engine head 112 may need different coolant fluid flow rates. For example, the engine block 110 and the engine head 112 each require a minimum zone flow to avoid boiling the coolant fluid and to prevent high temperatures within each block, which may cause damage thereto. Accordingly, the BRV 162 is introduced between an outlet of the engine block 110 and an inlet of the FCV 160 so that the BRV 162 is in fluid communication with the engine block 110 and the FCV 160. The BRV 162 is controllable by the valve controller 102 to provide the ability to flow coolant fluid through each of the engine block 110 and the engine head 112 at different rates. The valve controller 102 converts a flow request for coolant fluid flow through each of the engine block 110 and the engine head 112 to an actuator command to control the FCV 160 and/or the BRV 162. This ensures the correct flow of coolant fluid in each zone of the vehicle engine 100.

The valve controller 102 can continuously regulate the FCV 160 and the BRV 162 to adjust the flow of coolant fluid that the pump 104 can provide through the engine block 110 and the engine head 112. For example, the valve controller 102 can calculate a minimum zone flow rate of the coolant fluid for a zone in the vehicle engine 100. The minimum zone flow rate enables each of the zones of the vehicle engine 100 to act as a heat exchanger while avoiding coolant boiling. The minimum zone flow rate can be converted by the valve controller 102 into a desired actuator position for the FCV 160 to enable the FCV 160 to provide the minimum zone flow rate to the zone of the vehicle engine 100.

With continuing reference to FIG. 1, in embodiments of the present disclosure, the valve controller 102 can be a combination of hardware and programming. The programming may be processor executable instructions stored on a tangible memory, and the hardware can include a processing device for executing those instructions. Thus a system memory can store program instructions that when executed by the processing device implement the functionality described herein. Other engines/modules/controllers may also be utilized to include other features and functionality described in other examples herein. Alternatively or additionally, the valve controller 102 can be implemented as dedicated hardware, such as one or more integrated circuits, Application Specific Integrated Circuits (ASICs), Application Specific Special Processors (ASSPs), Field Programmable Gate Arrays (FPGAs), or any combination of the foregoing examples of dedicated hardware, for performing the techniques described herein.

FIG. 2 depicts a flow diagram of a method 200 for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine (e.g., the vehicle engine 100), according to embodiments of the present disclosure. The method 200 may be implemented, for example, by the valve controller of FIG. 1, by the processing system 500 of FIG. 5 (described below), or by another suitable processing system or device.

At block 202, the valve controller 102 (e.g., a processing device or system) calculates a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the vehicle engine 100. According to embodiments of the present disclosure, calculating the minimum zone flow rate for a zone is based on a coolant temperature measured at an inlet of the zone (e.g., an inlet at the engine head 112 for the engine head zone) and based at least in part on a heat flow in the zone. The heat flow indicates how much heat the particular zone can exchange.

For the engine block 110 zone, the minimum zone flow rate can be calculated according to the engine inlet coolant temperature and a combustion heat flow based on the engine speed (RPM) and total fuel burned. For the engine head 112 zone, the minimum zone flow rate can be calculated according to the engine inlet coolant temperature and a combustion heat flow based on the engine speed (RPM) and total fuel burned. For a low-pressure exhaust (LPE) zone (part of the other components 114), the minimum flow rate can be calculated according to an inlet coolant temperature at an inlet of the LPE and the heat flow rate of the LPE. For a turbo compressor zone (part of the other components 114), the minimum zone flow rate can be calculated according to an inlet coolant temperature at the inlet of the turbo compressor and a heat flow rate of the turbo compressor.

At block 204, the valve controller 102 converts the minimum zone flow rate into a desired actuator position for the FCV 160 to enable the FCV 160 to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system. FIG. 3A depicts a block diagram of an invertible flow model 300 for determining estimated flow of the FCV 160, according to embodiments of the present disclosure. According to embodiments of the present disclosure, a model based approach (e.g., the invertible flow model 300) can be used to determine estimated flows (302) based on various actuator positions of the FCV 160 (304), various positions of the main rotary valve 130 (306), and various speeds of the pump 104 (308). The invertible flow model 300 can also consider a mode of the main rotary valve 130 (e.g., an oil cooling mode, an oil warming mode, etc.) (310).

According to an embodiment of the present disclosure, the estimated flows 302 can be calculated using the following formula (one for each zone flow estimation):

flow=Base@200 RPM*(K2*RPM² +K1*RPM)

where K1 and K2 are constants describing characteristics of the pump 104 and shared by the different possible flows. RPM represents the speed of the pump 104 in revolutions per minute. Base@2000 RPM is a three variable structure that is based on the effective area of the FCV 160, the effective area of the opening of the radiator 120, and the mode of the main rotary valve 130 when the speed of the pump 104 is 2000 RPM. Accordingly, the estimated flow 302 is calculated.

The invertible flow model 300 can be inverted to create an inverted flow model 320 as depicted in FIG. 3B, according to embodiments of the present disclosure. The invertible flow model 320 can be used to convert a flow request (e.g., a minimum zone flow rate) (322) into an actuator position (324) for the FCV 160. The inverted flow model 320 considers the flow request (322), the speed of the pump 104 (326), the mode of the main rotary valve 130 (328), and an actuator position of the main rotary valve 130 (330) to convert the flow request into the desired actuator position (324) for the FCV 160.

The valve controller 102 operates in a flow domain to uncouple a request from a zone (e.g., engine head, engine block, LPE, turbo charger, cabin heater, etc.) from actuators for the various valves in the cooling system. Depending on the flow request and the valve, the inverted flow model 320 is able to convert a flow request in terms of flow into a position of the corresponding valve and vice versa. Accordingly, the entire cooling system can be calibrated without having a complete vehicle coolant circuit. It is enough to update the inverted flow model 320. By operating in the flow domain, the cooling system is enabled to implement the flow strategy described herein for each component/zone.

Continuing with reference to FIG. 2, at block 206, the valve controller 102 enables the FCV 160 to change from a current actuator position to the desired actuator position. That is, the valve controller 102 sends a signal to the FCV 160 to cause the FCV to change actuator positions to the desired actuator position. For example, the FCV 160 may be 80% open, and the valve controller 102 can send a signal to the FCV 160 to change to only 30% open.

Additional processes also may be included, and it should be understood that the processes depicted in FIG. 2 represent illustrations and that other processes may be added or existing processes may be removed, modified, or rearranged without departing from the scope and spirit of the present disclosure.

FIG. 4 depicts a flow diagram of a method 400 for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine, according to embodiments of the present disclosure. The method 400 may be implemented, for example, by the valve controller of FIG. 1, by the processing system 500 of FIG. 5 (described below), or by another suitable processing system or device.

At block 406, a minimum zone flow rate 408 is calculated based on a coolant fluid temperature at an inlet of a zone 402 and a heat flow for the zone 404. The minimum zone flow rate 408 is compensated for ambient pressure information 412 at block 410. This enables the vehicle engine 100 to operate in a safe condition at varying altitudes (with varying ambient pressures) by reducing coolant fluid temperature differences across each zone by increasing the flow of coolant fluid through each zone. At block 416, the ambient pressure compensated minimum zone flow rate 414 is then converted into a desired actuator position 418 for the FCV 160 using an invented flow model (e.g., the inverted flow model 320 of FIG. 3B).

At block 420, the desired actuator position 418 can be adjusted to an adjusted desired actuator position 424 if the zone is an engine head zone for the engine head 112. If the zone is not the engine head zone, the desired actuator position 418 is output to the FCV 160 to cause the FCV 160 to change to desired actuator position. If, however, the zone is the engine head zone, the desired actuator position 418 is adjusted to the adjusted desired actuator position 424 based on the radiator flow rate 422.

These techniques aid temperature control by correlating the FCV 160 and the main rotary valve 130 to increase coolant flow through the vehicle engine 100 when a request for increased flow of coolant flow to the radiator occurs. This prevents radiator flow saturation. For example, even if the main rotary valve 130 is opening more than the line to the radiator 120, the FCV 160 determines the maximum amount of flow of coolant fluid that is allowed through the vehicle engine 100, including the radiator 120. This also increases the cooling capability of the radiator 120 by flowing more coolant fluid through the radiator 120, which has higher heat exchange efficiency than the other zones of the vehicle engine 100. This also reduces the temperature cycling of the radiator 120, which can be harmful to the radiator, because in cases of high cooling demand, the FCV can aid the system by increasing the heat exchange in zones of the vehicle engine 100. This reduces the temperature change across the radiator 120.

Additional processes also may be included, and it should be understood that the processes depicted in FIG. 4 represent illustrations and that other processes may be added or existing processes may be removed, modified, or rearranged without departing from the scope and spirit of the present disclosure.

It is understood that the present disclosure is capable of being implemented in conjunction with any other type of computing environment now known or later developed. For example, FIG. 5 illustrates a block diagram of a processing system 500 for implementing the techniques described herein. In examples, processing system 500 has one or more central processing units (processors) 21 a, 21 b, 21 c, etc. (collectively or generically referred to as processor(s) 21 and/or as processing device(s)). In aspects of the present disclosure, each processor 21 may include a reduced instruction set computer (RISC) microprocessor. Processors 21 are coupled to system memory (e.g., random access memory (RAM) 24) and various other components via a system bus 33. Read only memory (ROM) 22 is coupled to system bus 33 and may include a basic input/output system (BIOS), which controls certain basic functions of processing system 500.

Further illustrated are an input/output (I/O) adapter 27 and a network adapter 26 coupled to system bus 33. I/O adapter 27 may be a small computer system interface (SCSI) adapter that communicates with a hard disk 23 and/or another storage drive 25 or any other similar component. I/O adapter 27, hard disk 23, and storage device 25 are collectively referred to herein as mass storage 34. Operating system 40 for execution on processing system 500 may be stored in mass storage 34. A network adapter 26 interconnects system bus 33 with an outside network 36 enabling processing system 500 to communicate with other such systems.

A display (e.g., a display monitor) 35 is connected to system bus 33 by display adapter 32, which may include a graphics adapter to improve the performance of graphics intensive applications and a video controller. In one aspect of the present disclosure, adapters 26, 27, and/or 32 may be connected to one or more I/O busses that are connected to system bus 33 via an intermediate bus bridge (not shown). Suitable I/O buses for connecting peripheral devices such as hard disk controllers, network adapters, and graphics adapters typically include common protocols, such as the Peripheral Component Interconnect (PCI). Additional input/output devices are shown as connected to system bus 33 via user interface adapter 28 and display adapter 32. A keyboard 29, mouse 30, and speaker 31 may be interconnected to system bus 33 via user interface adapter 28, which may include, for example, a Super I/O chip integrating multiple device adapters into a single integrated circuit.

In some aspects of the present disclosure, processing system 500 includes a graphics processing unit 37. Graphics processing unit 37 is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display. In general, graphics processing unit 37 is very efficient at manipulating computer graphics and image processing, and has a highly parallel structure that makes it more effective than general-purpose CPUs for algorithms where processing of large blocks of data is done in parallel.

Thus, as configured herein, processing system 500 includes processing capability in the form of processors 21, storage capability including system memory (e.g., RAM 24), and mass storage 34, input means such as keyboard 29 and mouse 30, and output capability including speaker 31 and display 35. In some aspects of the present disclosure, a portion of system memory (e.g., RAM 24) and mass storage 34 collectively store an operating system to coordinate the functions of the various components shown in processing system 500.

The descriptions of the various examples of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described techniques. The terminology used herein was chosen to best explain the principles of the present techniques, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the techniques disclosed herein.

While the above disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the present techniques not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope of the application. 

1. A computer-implemented method for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine, the method comprising: calculating, by a processing device, a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the internal combustion engine; converting, by the processing device, the minimum zone flow rate into a desired actuator position for a flow control valve to enable the flow control valve to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system; and enabling, by the processing device, the flow control valve to change from a current actuator position to the desired actuator position, wherein an outlet of the flow control valve is in fluid communication with an inlet of a main rotary valve comprising a first outlet in fluid communication with a radiator bypass and a second outlet in fluid communication with a radiator.
 2. The computer-implemented method of claim 1, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a coolant fluid temperature at an inlet of the zone.
 3. The computer-implemented method of claim 1, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a heat flow in the zone.
 4. The computer-implemented method of claim 1, further comprising adjusting the minimum zone flow rate based at least in part on ambient pressure information.
 5. The computer-implemented method of claim 1, wherein the zone of the cooling system is an engine head zone.
 6. The computer-implemented method of claim 5, further comprising revising the desired actuator position for the flow control valve based at least in part on a radiator flow rate.
 7. The computer-implemented method of claim 1, wherein converting the minimum zone flow rate into a desired actuator position is based at least in part on an inverted flow model.
 8. The computer-implemented method of claim 1, wherein the desired actuator position is a percentage of opening of the flow control valve.
 9. A system for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine, the system comprising: a memory comprising computer readable instructions; and a processing device for executing the computer readable instructions for performing a method, the method comprising: calculating, by the processing device, a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the internal combustion engine; converting, by the processing device, the minimum zone flow rate into a desired actuator position for a flow control valve to enable the flow control valve to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system; and enabling, by the processing device, the flow control valve to change from a current actuator position to the desired actuator position, wherein an outlet of the flow control valve is in fluid communication with an inlet of a main rotary valve comprising a first outlet in fluid communication with a radiator bypass and a second outlet in fluid communication with a radiator.
 10. The system of claim 9, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a coolant fluid temperature at an inlet of the zone.
 11. The system of claim 9, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a heat flow in the zone.
 12. The system of claim 9, the method further comprising adjusting the minimum zone flow rate based at least in part on ambient pressure information.
 13. The system of claim 9, wherein the zone of the cooling system is an engine head zone.
 14. The system of claim 13, the method further comprising revising the desired actuator position for the flow control valve based at least in part on a radiator flow rate.
 15. The system of claim 9, wherein converting the minimum zone flow rate into a desired actuator position is based at least in part on an inverted flow model.
 16. The system of claim 9, wherein the desired actuator position is a percentage of opening of the flow control valve.
 17. A computer program product for controlling a flow of a coolant fluid through a cooling system of an internal combustion engine, the computer program product comprising: a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a processing device to cause the processing device to perform a method comprising: calculating, by the processing device, a minimum zone flow rate of the coolant fluid for a zone of a cooling system of the internal combustion engine; converting, by the processing device, the minimum zone flow rate into a desired actuator position for a flow control valve to enable the flow control valve to provide the minimum zone flow rate of the coolant fluid to the zone of the cooling system; and enabling, by the processing device, the flow control valve to change from a current actuator position to the desired actuator position, wherein an outlet of the flow control valve is in fluid communication with an inlet of a main rotary valve comprising a first outlet in fluid communication with a radiator bypass and a second outlet in fluid communication with a radiator.
 18. The computer program product of claim 17, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a coolant fluid temperature at an inlet of the zone.
 19. The computer program product of claim 17, wherein calculating the minimum zone flow rate of the coolant fluid for the zone of the cooling system is based at least in part on a heat flow in the zone.
 20. The computer program product of claim 17, the method further comprising adjusting the minimum zone flow rate based at least in part on ambient pressure information. 